Road roller



Aug. 10, 1937.

A. W. AITKEN ROAD ROLLER Filed Dec. 27, 1954 2 Sheets-Sheet l Auglfl,1937. w, A|TKEN I Q I 2,089,591

ROAD ROLLER Filed Dec. 27, 1934 2 Sheets-Sheet 2 mifQzQ Patented Aug.10, 1937 UNITED srarn hdwdl ROAD ROLLER Application December 27, 1934,Serial No. 759,391

11 Claims.

This invention is a novel improvement in road rollers of the type shownin the copending joint application of Carl F. Greiner and Andrew W.Aitken, Serial No. 754,166 filed November 21, 1934.

which application disclosed a road roller of the three-axle type havinga rear wheeled driving axle, and having front and intermediate rollsboth arranged for simultaneous steering. The king pin of the yoke forthe front roll was pro- 19 vided with a removable collar normallymaintaining the yoke in such position that the lower periphery of thefront roll was disposed in a plane tangent to the lower peripheries ofthe intermediate roll and rear wheels, but when the collar was removedthe front yoke was permitted to shift vertically with respect to thevehicle frame so that the front roll could rise and fall with respect tothe said plane when the vehicle was operated upon uneven roads, forotherwise 20 in such three-axle type road rollers the intermediate rollwhen engaging a crest or raised portion in the road would act as afulcrum, and as it would have to carry the weight of the front roll theroad roller frame would tend to tilt forwardly 5 thereby removing therequisite weight on the rear driving roll or wheels for propulsion.

i The principal objects of my present invention are to provide ahorizontally disposed lever pivoted adjacent the king pin (in place ofthe removable collar disclosed in said joint application), said leverhaving a recess in one edge and being adapted to be swung into positionto engage a reduced portion of the king pin of the front yoke, and whenso engaged to maintain the lower pe- 5 riphery of the front roll in theplane of the lower peripheries of the intermediate roll and drivingrolls or wheels; also to provide an operating rod attached to the leveradapted to engage and disengage the lever and king pin; also a springnormally urging the lever to swing towards the king pin,.whereby whenthe road roller is operating on a plane surface, the lever will be ormay be engaged with the reduced portion of the king pin, thus preventingany relative vertical movement between the front roll and the vehicleframe, but when the road roller is operating on an uneven road surface,the lever may be readily disengaged from the king pin by operation ofthe rod, permitting the front roll to rise and fall to suit theunevenness of road surface, thus relieving the front end of the frame ofthe necessity of supporting the weight of the front roll when the'intermediate roll is operating on a raised portion of the road. Anotherobject of my invention is to provide a novel road surface indicator bywhich the opera tor may readily and visually determine when he hasrolled a plane surface or rolled a surface to conform withspecifications, said indicator comprising a vertical rod having itslower end resting on a plate fastened to the king post of the frontyoke, so that same will rise and fall by and with the front roll, saidrod being slidably mounted in bearings provided in an indicator framemounted at the front end of the road roller frame. An indicator platewithin the frame marked with indicia cooperates with a plate on theupper end of the rod whereby if the lever is disengaged from the kingpin the operator may visually determine by the position of the plate ofthe rod with respect to the indicia plate of the frame whether or notthe road surface has been rolled to a plane surface, or whether or notthe road surface is irregular; and hence by watching the indicator afterthe road surface is rolled, the operator will know the condition of theroad, i. e. whether or not the rolling is according to roadspecifications, or whether more material will have to be distributed inplaces and such places re-rolled.

I will explain the invention with reference to the accompanying drawingswhich illustrate one practical embodiment thereof to enable othersfamiliar with the art to adopt and use the same; and will summarize inthe claims the novel features of construction and novel combination ofparts for which protection is desired.

In said drawings:

Fig. 1 is a side elevation of a road roller (foreshortened) showing thelever engaged and all the rolls and wheels operating on a plane surface.

Fig. 2 is a fragmentary view of the front roll yoke with leverdisengaged and the front yoke dropped in its trunnion.

Fig. 3 is a top plan view of the forward portion of the road roller.

Fig. i is a section on the line 44, Fig. 1.

Fig. 5 is an enlarged front elevation of the road surface indicator.

Fig. 6 is a side elevation of the indicator.

As shown, the road roller is of the three-axle type and comprisesparallel side frames A, carrying journals adjacent their rear ends forthe rear axle B which carries the driving wheels or rolls C, and in rearof the driving rolls or wheels C is the operators platform E. Motor 13is mounted in the side frames A and drives axle B in the usual manner.The forward ends of side frames A are arched upwardly as at A over theintermediate roll 1, and parallel extension frame members I, I, aresecured to the forward ends A of the side frames, said members i, I,carrying the trunnion castings 2 and 3 arranged in tandem relation andwhich receive the king pins 4a,, 5a of the yokes 8 and 5 for front roll6 and interme- 5 diate roll 1.

Both yokes 4 and 5 are arranged for simultaneous steering. As shown onthe upper end of king pin 4a. of the front yoke i is an arm 8 connectedby a link 3 to a pin Illa on a worm gear 10 segment It! mounted on apivot pin Nib journaled in cross-plates ii extending between the framemembers I. Similarly the upper end of king pin Ewof the intermediateyoke 5 carries an arm I? connected by link l3 to a pin I60 on the worml5 gear segment Hi, the arrangement of links and levers being such thatmovement of the segment It will pivot both yokes 4 and 5 simultaneously,

but as the pin lilo is disposed nearer the pivot lflbof the gear segmentthan is the pin In the turning movement of the front yoke 4 will beproportionately greater than that of the yoke 5.

J ournaled in bracket I an on the frame member 1,

and meshing with the worm gear segment 59, is a worm I5 on a steeringrod it which extends upwardly and rearwardly to a position above theoperators platform E, said rod having a hand crank 16a on its upper endwhereby worm it may be rotated to turn the gear segment it.

The intermediate roll 'l' under ordinary work- 00 ing conditions is notpermitted any vertical or tilting movement with respect to the roadroller frame, and for this purpose the upper face of yoke 5 is providedwith removable rolls 2!] (Fig.1) engaging removable rubbing plates I 8mounted on the un dersides of the frame members i l, or with other meansfor normally holding the horizontal plane of the axle of theintermediate roll 1 parallel with the driving axle B; however whentransporting the road roller over rough roads, or when turning the roadroller around, the rolls 2D and plates It may be removed to permit theintermediate roll i to pivot or tilt laterally on its hori-- zontalpivot pin 5x (Fig. l) in order to minimize strains in the road rollerframe, or in the yoke 5 or trunnion 3.

Adjacent the front trunnion casting 2 is a horizontally disposedbell-crank lever 22, pivoted as at 23 to a plate 2!, said bell-cranklever having one arm 22a provided with a recess 2% in its side adaptedwhen the arm is swung towards king pin id to engage a reduced portion41' of the king pin as shown in Fig. 1 disposed between the top oftrunnion casting 2 and the steering arm 8, the thickness of the arm 2212at the recess 222; being slightly less than the length of the recessedportion M of the king pin in order to prevent vertical movement of theking pin to with respect to trunnion 2 when the lever 22a is thusengaged. The other arm 220 of the bell-crank lever 22 is at- 0 tached toan operating rod 26 extending rearwardly to a position accessible fromthe operators platform E and the rod may be provided withv a catch (notshown) for holding the lever arm 22a out of engagement with the king pinta.

5 A spring 25 attached to the arm 22a and to a bracket 2e on the plate2! normally yieldably urges the bell-crank lever 22 to swing so as toengage its recess 22b with the king pin to, in which position the lowerperipheries of the front,

70 intermediate, and rear rolls lie in the same plane, and no verticalmovement of the front roll 6 with respect to the frame of the roadroller will be pe mitted. The spring 25 normally urges the bellcranklever 22 to engage the king pin when the 75 reduced portion 47' of theking pin is disposed opposite the recessed arm 22a, 1. 'e., between theupper face of the trunnion casting 2 and the underside of the steeringarm 8, and the spring 25 holds the lever 22 such position until thebell-crank lever is manually shifted through rod 2 3 by the operator andthe catch (not shown) at the operators platform actuated to hold thelever 22 in such disengaged position.

Fig. 2 shows the position of the front roll 5 relative to the frame I, iof the road roller when the lever 22 is disengaged on the rolleroperating on an uneven road surface, the front yoke and roll being showndisposed at a lower level than the position shown in Fig. l, the kingpin in of the yoke having dropped in the trunnion casting 2 an amountequal to the distance marked a: in

, Fig. 2, Hence when lever 22a is disengaged from the king pin tn theextension members i of the vehicle frame will not have to carry theweight of the forward yoke and roll in event the intermediate roll ishould encounter a high point in the road surface.

I also provide a novel road surface indicator to enable the operator toreadily and visibh determine whether or not he has rolled a planesurface, or rolled to required specifications. The indicator consists ofa casing 2'? bolted or otherwise secured to the front of the trunnioncasting 2, said casing consisting of a rectangular frame as shown inFigs. 5 and 6 having a lower bearing 28 and an upper bearing 2:;receiving a vertically disposed rod 3i? which is slidably mounted in thebearings 28, 29, the lower end of the rod 33 resting on a plate 3!secured to theking pin a, the

plate 3! being of such shape and dimensions that the lower end of rod3E3 will rest thereon'throughout the steering movement of the yoke 5.Thus the u per end of rod Sil will rise and fall with the front roll 5while the casing 27 has a fixed relation to the road roller frame. Onthe upper end of rod 3%? is a plate 32 preferably colored black, whichplate moves vertically with the rod 3| across a plate 33 forming abackground at the upper end of the casing 27. A spring 36 around rod 39within the bracket frame 'fi bearing against the bearing 2i? and againstacollar 3? on the rod 3t normaily'tends to maintain the rod 36 depressedupon the plate 35. The background 33 is preferably of generai'white orlight colorbut is provided with a black or darkened field 345 whichstands out visibly on the white background 33, the black area it beingof size and shapejsirnilar to the plateSQ carried by rod 39, and beingdisposed in such elevation on the background 33 that when the plate 32overlies the black field 34 the lower peripheries of the three rolls 6,l and wheels B all lie in the same plane. When the three rollers do notlie in the same plane part of the white background 33 will be visiblebetween the black plate 32 and the black field 34, which occurrence willdenote that the. surface being rolled is not a plane surface.

The indicator feature is important in that when the road surface has benrolled .to a plane, with arm 22a disengaged from the king pin '40., nowhite will appear on the indicator between the black field 3 and blackplate 32 while the road roller is moving. If a fluctuating width ofwhite appears on the indicator between the black areas or fields theoperator will know that the road surface is irregular or not a planesurface. Thus by watching the indicator the operator may visiblydetermine the condition of the road surface, and if more white shows onthe indicator between the black fields than the road specificationallows,

then loose material will have to be distributed and re-rolled until noneor but little white background 33 appears between the black fields32-34.

5 I do not limit my invention to the exact form shown in the drawings,for obviously changes may be made therein within the scope of theclaims.

I claim:

1. In a road roller, a frame supported upon two rollers and providedwith a vertically movable third roller; means for locking the thirdroller in such position that its lower periphery lies in the plane ofthe lower peripheries of the supporting rollers whereby the road rollermay roll a plane surface; and indicating means associated with the thirdroller for indicating high and low spots in the road surface when saidlocking means is disengaged to permit the third roller to shiftvertically.

2. In a road roller as set forth in claim 1, said indicating meanscomprising a plate carried by the frame; a member slidably mounted onthe plate and operated by and with the rise and fall of the thirdroller; and indicia on the plate 00- operating with a portion of saidmember.

3. In a road roller as set forth in claim 1, said indicating meanscomprising a bracket mounted on the frame; a rod slidably mounted in thebracket and operated by the rise and fall of the third roller; andindicia on the bracket cooperating with the upper end of the rod.

4. In a road roller, 2. frame; a wheeled rear driving axle journaledtherein; a pair of trunnions mounted in the frame in tandem relation inadvance of the axle; steering yokes pivoted in the trunnions; groundrollers carried by the yokes; means adapted to engage the front yoke formaintaining the lower periphery of the front roller in the plane of thelower peripheries of the 4.0 other roller and wheels, said means whendisengaged permitting the front roller to shift vertically with respectto said plane; means for operating said maintaining means; and means toindicate to the operator high and low spots in 45 the road surface whenthe maintaining means is disengaged.

' 5. In a road roller as set forth in claim 4, said maintaining meanscomprising a lever pivoted on the frame adapted when swung to engage are- 5 duced portion on the pivot of the front yoke to prevent verticalmovement of the pivot in said trunnion.

6. In a road roller as set forth in claim 4, said maintaining meanscomprising a lever pivoted on the frame having an open recess adapted toen gage a reduced portion on the pivot of the front yoke to preventvertical movement of the yoke in said trunnion.

I. In a road roller as set forth in claim 4, said indicating meanscomprising a bracket carried by the frame adjacent the front yoke; amember vertically slidably mounted in the bracket and having its lowerend engaging the front yoke; and indicia on the bracket cooperating withthe upper end of said member, for indicating the rise and fall of thefront roller with respect to the frame.

8. In a road roller as set forth in claim 4, said front rollermaintaining means comprising a bellcrank lever pivoted on the framehaving one arm provided with an open recess adapted when the lever isswung to engage a reduced portion on the pivot of the front yoke toprevent vertical movement of the pivot in said trunnion; an operatingrod connected with the other arm of said lever; and means for yieldablyurging the recessed arm into engagement with the yoke.

9. In a road roller, a frame; a wheeled rear driving axle journaledtherein; a pair of trunnions mounted in the frame in tandem relation inadvance of the axle; steering yokes pivoted in the trunnions; groundrollers carried by the yokes; a lever pivoted on the frame adapted whenswung to engage a reduced portion on the pivot of the front yoke toprevent vertical movement of the pivot in said trunnion whilemaintaining the lower periphery of the front roller in the plane of thelower peripheries of the other roller and wheels, said lever whendisengaged permitting the front roller to shift vertically with respectto said plane; and means for operating said lever.

10. In a road roller as set forth in claim 9, said lever having an openrecess adapted to engage the reduced portion on the pivot of the frontyoke.

11. In a road roller as set forth in claim 9, said lever comprising abell-crank lever pivoted on the frame having one arm provided with anopen recess adapted to engage said reduced portion on the pivot of thefront yoke; and said lever operating means comprising an operating rodconnected with the other arm of said lever; and means for yieldablyurging the recessed arm into engagement with the yoke.

ANDREW W. AITKEN.

